1. Field of the Invention
The present invention relates to a disk reproducing apparatus capable of loading two different kinds of cartridges designed to different specifications, and used for an information storage device such as a data file storage device or an image file storage device, and also relates to a compatible cartridge used with the same apparatus.
2. Description of the Related Art
Write-once and rewritable optical disks are provided, each permanently encased in a cartridge to protect the optical disk from dust and other foreign particles. A prior known cartridge will be described with reference to FIGS. 15 and 16.
FIG. 15 shows an example of a conventional, single-sided cartridge. FIG. 15 is a perspective view showing a cartridge 101 (hereinafter referred to as the MO cartridge), with its front surface facing up, that conforms to international standards defining a 90-mm magneto-optical disk. FIG. 16 is a perspective view of the same MO cartridge 101 with its back surface facing up.
The MO cartridge 101 consists primarily of a case body 102 encasing a single-sided 90-mm magneto-optical disk with a substrate thickness of 1.2 mm (hereinafter referred to as the MO disk), and a U-shaped shutter 104 fixed to a slider 103 slidably mounted to the case body 102.
The outer dimensions of the MO cartridge 101 are 90 mm in length, 94 mm in depth, and 6 mm in height. The front surface of the case body 102 has a first opening 105 through which a bias magnet is inserted and positioned inside the case body 102 during recording or reproducing. On the back surface of the case body 102, there is formed a second opening 106, through which a disk motor and an optical pickup are inserted and positioned inside the case body 102. On the back surface, there are formed positioning holes 107 and reference faces 108 used to hold the MO cartridge 101 in position.
In both side faces of the case body 102 are formed slots 109 for an autochanger and semi-circular recesses 110 for auto loading. A corner notch 111 is formed on one corner of the inserting side of the case body 102 to prevent the MO cartridge 101 from being inserted incorrectly.
The shutter 104, constructed to slide over the outer surfaces of the case body 102, is urged by a torsion spring (not shown) installed inside the case body 102 in a direction that closes the first opening 105 and second opening 106. The back end of the U-shaped shutter 104 is held by a shutter holding plate 112 so as to be guided therealong in sliding fashion
Next, a prior art loading mechanism designed to accommodate the above-described MO cartridge 101 will be described with reference to FIG. 17.
FIG. 17 is a perspective view showing the prior art MO cartridge loading mechanism. In FIG. 17, arrow Y indicates the direction in which the MO cartridge 101 is inserted.
A cartridge holder 121 for holding the MO cartridge 101 in position is shaped in the form of a tray with both sides thereof bent as shown. A support shaft 122 is formed in protruding fashion on the right rear corner (the uppermost portion in FIG. 17) of the cartridge holder 121. On this support shaft 122 there is mounted a shutter opener 123 having a shutter opener pin 123a at its end. The shutter opener 123 is pivotably supported on the support shaft 122 and is urged in the direction of arrow X by a torsion spring 124. On the left rear corner of the cartridge holder 121, a pawl 125 is formed in an inwardly protruding fashion for preventing the MO cartridge 101 from being inserted incorrectly.
Next, the loading operation of the MO cartridge 101 will be described.
When the MO cartridge 101, with its front surface facing up, is inserted into the cartridge holder 121 of FIG. 17 in the direction of the arrow Y, the shutter opener pin 123a on the shutter opener 123 comes into contact with the rightmost end of the slider 103 on the MO cartridge 101. As the MO cartridge 101 is further inserted, the inserting force causes the shutter opener pin 123a to push the rightmost end of the slider 103, thus causing the slider 103 to slide along the case body 2. By moving the slider 103 against the force of the torsion spring 124 in this way, the shutter 104 is moved in the direction that opens the first opening 105 and second opening 106.
When the MO cartridge 101 is further inserted into the cartridge holder 121, the first opening 105 and second opening 106 become completely exposed, and the shutter opening operation is thus completed.
When the shutter opening operation is completed, the MO cartridge 101 is positioned with its notch 111 facing the pawl 125 of the cartridge holder 121. The pawl 125, however, is not in contact with the notch 111, and the MO cartridge 101 can thus be inserted as far as to the prescribed position.
After the shutter opening operation is completed, positioning pins (not shown) provided inside the apparatus are inserted in the positioning holes 107 formed in the inserted MO cartridge 101. At the same time, reference posts (not shown) provided inside the apparatus abut against the reference faces 108 formed on the case body 102, thus holding the inserted MO cartridge 101 in position. Also at this time, the clamping face of the MO disk inside the MO cartridge 101 is mounted on the turn table of the disk motor, and the loading operation of the MO cartridge 101 is thus completed.
Disk mounting distance (hereinafter referred to as L1), which is the distance from the reference faces 108 on the case body 102 of the MO cartridge 101 to the clamping face of the MO disk, is specified as 2.4 mm by the standard defining the MO cartridge 101.
Next, an operation will be described when the MO cartridge 101 is inserted upside down or backwards into the cartridge holder 121. When the MO cartridge 101 is inserted in the cartridge holder 121 in such an abnormal manner, the shutter 104 cannot be opened by the shutter opener pin 123a because the shutter opener pin 123a does not come into contact with the rightmost end of the slider 103 on the MO cartridge 101.
Furthermore, since a corner other than the corner notch 111 of the MO cartridge 101 strikes against the incorrect insertion prevention pawl 125 in the cartridge holder 121, the MO cartridge 101 cannot be inserted as far as to the correct position. Accordingly, the positioning pins inside the apparatus do not engage with the positioning holes 107.
In this way, when the MO cartridge 101 is incorrectly inserted, the shutter 104 is not opened, and the MO cartridge 101 cannot be loaded with its shutter 104 prevented from being opened.
With increasing demand for higher-density of recording and thinner optical disks in recent years, a double-sided disk formed from two disk substrates each with 0.6 mm thickness laminated together has been developed. A double-sided cartridge for housing such a double-sided disk is disclosed, for example, in Japanese Patent Unexamined Publication No. Hei 6-267226.
Such a prior known double-sided cartridge will be referred to simply as the double-sided cartridge, as opposed to the MO cartridge. The construction of the double-sided cartridge will be described below with reference to FIG. 18, which is a perspective view showing the double-sided cartridge 131 containing therein a double-sided disk. The construction of the double-sided cartridge 131 is substantially the same both on its front and back. For simplicity, the explanation will be given using FIG. 18 that shows the double-sided cartridge 131 with its front surface facing up.
This prior art double-sided cartridge 131 consists primarily of a case body 132 and a U-shaped shutter 133 fixed to a slider (not shown) slidably supported inside the case body 132. The outer dimensions of the double-sided cartridge 131 are 90 mm in width, 94 mm in length, and 5 mm in height. The front and back surfaces of the case body 132 each have an opening through which the disk motor and optical pickup are inserted and positioned inside the case body 132. Further, on both the front and back surfaces of the case body 132, there are formed positioning holes 135 and reference faces 136 for positioning the double-sided cartridge 131 in prescribed loading position. A groove 137 is formed on each of the right and left sides of the case body 132 in the forward portion thereof as viewed in the direction of the disk insertion. A slot 138 for an autochanger is formed on each of the right and left sides of the case body 132 in the rearward portion thereof.
An opener belt 139 connected to the shutter 133 via the slider is slidably guided along one of the grooves 137 formed on both sides of the case body 132. A shutter opener hook 140 is attached to one end of the opener belt 139.
The shutter 133 is urged by a torsion spring (not shown) installed inside the case body 132 in such a direction as to open an opening 134. Both ends of the U-shaped shutter 133 are held and guided in sliding fashion between shutter holding plates 141 mounted on the outer surfaces of the case body 132.
The opening 134, positioning holes 135, and reference faces 136 formed in the case body 132 are identical in shape and position to the corresponding portions of the earlier described MO cartridge 101. However, because of the double-sided construction, the double-sided cartridge 131 does not have the corner notch 111 nor the auto loading semi-circular recesses 110 of the MO cartridge 101.
Next, a prior art loading mechanism designed to accommodate the above-described double-sided cartridge 131 will be described with reference to FIG. 19. FIG. 19 is a perspective view showing one example of a prior art double-sided cartridge loading mechanism.
A cartridge holder 151 for holding the double-sided cartridge 131 is shaped in the form of a tray by using a plate with both sides thereof bent as shown. On each side of the cartridge holder 151 is formed a shutter opener pawl 152 that can enter the groove 137 on the double-sided cartridge 131 and can engage on the opener hook 140.
Next, the operation to insert the double-sided cartridge 131 in the cartridge holder 151 will be described.
When the double-sided cartridge 131 is inserted into the cartridge holder 151, the shutter opener pawl 152 of the cartridge holder 151 enters the groove 137 of the case body 132 and engages on the shutter opener hook 140. As the double-sided cartridge 131 is further inserted into the cartridge holder 151, the shutter opener hook 140 is pressed against the shutter opener pawl 152 by the inserting force of the double-sided cartridge 131. This causes the opener belt 139 connected to the shutter opener hook 140 to move, sliding along the groove 137 against the force of the torsion spring installed inside the case body 132. As a result, the shutter 133 on the case body 132 moves in the direction that opens the opening 134.
When the double-sided cartridge 131 is still further inserted, the opening 134 is completely exposed, and the shutter opening operation is thus completed.
Upon completion of the shutter opening operation, the positioning pins provided inside the apparatus are inserted in the positioning holes 135 of the double-sided cartridge 131. At the same time, the reference posts inside the apparatus are made to abut against the reference faces 136 to hold the inserted double-cartridge 131 in position. The clamping face of the double-sided disk is then mounted on the turn table of the disk motor to complete the loading operation. In this case, the disk mounting distance (hereinafter referred to as L2), which is the distance from the reference faces 136 on the case body 132 to the clamping face of the double-sided disk, is 1.9 mm. L2 of the double-sided cartridge 131 is 0.5 mm shorter than L1 (2.4 mm) of the MO cartridge 101.
When the double-sided cartridge 131 is inserted upside down into the cartridge holder 151, the shutter opener pawl 152 formed on the opposite side engages on the shutter opener hook 140, and the same shutter opening operation as described above is performed. The shutter 133 is thus opened.
When the double-sided cartridge 131 is inserted with its rear end facing forward into the cartridge holder 151, the rear end corners of the case body 132 strike against the shutter opener pawls 152, and the double-sided cartridge 131 cannot be further inserted. Incorrect insertion of the disk is thus prevented.
As described above, the prior art loading mechanisms have been designed exclusively for either the MO cartridge or the double-sided cartridge. In the prior art, there have not been provided compatible loading mechanisms capable of loading both the MO cartridge 101 and the double-sided cartridge 131.
In recent years, in the field of optical disk technology, a demand has been increasing for compatible loading mechanisms that can load both the MO cartridge 101 and the double-sided cartridge 131.
However, there have been several problems as will be described below in the development of the compatible loading mechanism that can load both the MO cartridge 101 and the double-sided cartridge 131.
(1) The shutter opening system is different between the MO cartridge 101 and the double-sided cartridge 131. This has made it impossible to use either prior art loading mechanism as a compatible loading mechanism. More specifically, with the loading mechanism designed for the MO cartridge 101, the shutter 133 on the double-sided cartridge 131 cannot be opened. Furthermore, since the incorrect insertion prevention pawl 125 on the cartridge holder 121 strikes against a corner of the double-sided cartridge 131, the double-sided cartridge 131 cannot be inserted as far as to the prescribed position in the loading mechanism built for the MO cartridge 101.
On the other hand, with the loading mechanism designed for the double-sided cartridge 131, the shutter 104 on the MO cartridge 101 cannot be opened. Furthermore, since the shutter opener pawls 152 on the cartridge holder 151 strike against corners of the MO cartridge 101, the MO cartridge 101 cannot be inserted as far as to the prescribed position in the loading mechanism built for the double-sided cartridge 131.
(2) The thicknesses of the MO cartridge 101 and double-sided cartridge 131 are different by 1 mm. As a result, when the disk is mounted on the turn table, the disk mounting distance from the outer surface of the cartridge to the mounting surface of the disk is different by 0.5 mm between the MO cartridge 101 and the double-sided cartridge 131. This would require an adjusting mechanism to position the double-sided cartridge 131 0.5 mm higher than the MO cartridge 101, but neither the double-sided cartridge 131 nor the loading mechanism of the prior art has been equipped with such a mechanism to adjust the loading position of the inserted cartridge.